Hot-spot manifold



Feb. 19, 1946. ARDNE T 2,395,264

HOT SPOT MANIFOLD Filed Feb. 22, 1945 la la 51011 71281 INVENTOR.

N I y ATTORNEY.

Patented Feb. 19, i946 HOT-SPOT MANIFOLD Dale Gardner, Detroit, Mich, assignor to George M. Holley and Earl Holley Application February 22, 1945, Serial No. 579,265

2 Claims.

The object of this invention is to improve the distribution of the fuel in the air stream of an inlet manifold leading from an ordinary downdraft carburetor. At present, if the manifold is made big enough for maximum power, it is too big for normal driving. If it is made small enough for good distribution, it is too small for maximum power at top speed.

The figures show th preferred form of my invention.

Figure 1 shows a cross-sectional elevation on plane |l of Figure 2.

Figure 2 shows a cross-sectional elevation on plane 2--2 of Figure 1.

In the figures, 10 is the air entrance, II is the venturi therein, i2 is the mixture outlet, I3 is the throttle therein, M is the inlet manifold, I5 is the hot spot, I6 is an auxiliary throttle located downstream from throttle l3 and is located in an auxiliary outlet I'I leading to an auxiliary manifold I8. The two manifolds I4 and I8 discharge into the outlet ports l9 and 20. Throttle I6 is controlled by the lever 2i, which is connected to the rod '22, which in its turn is connected to the diaphragm 23. The chamber 24 above 23 is connected through the port 25 with the throat of the venturi II. A compression spring 26 pushes the rod 22 down and thus closes the throttle l6 under normal driving conditions.

Operation In the normal operation of the engine when the throttle I3 is opened, a fuel mixture flows from the venturi H through the manifold I4, flowing over the hot spot 15. At wide open throttle, the velocity of fiow through the venturi ll increases to such a degree that the suction in the chamber 24 compresses the spring 26 and the throttle It opens so that the mixture is admitted to the cold manifold 18. At low engine speed, wide open throttle, the throttle I 6 remains closed so that the mixture flows with considerable velocity to the inlet manifold 14. Hence, the distribution is good at low engine speed, wide open throttle and at all conditions of air fiow corresponding to ordinary normal running conditions. It is only when the throttle is wide open and the engine is traveling at a relatively high rate of speed, that is to say, over 35 miles per hour, that the throttle It opens.

When the throttle it opens, a relatively cold mixture is carried into the inlet manifold i3 so that the average mixture temperature falls and power is increased because of the lowered mixture temperature and higher mixture density. Inlet manifold I4 is made large enough so that during of the driving, the throttle it is closed.

What I claim is:

1. In an internal combustion engine having a plurality of inlet ports, a main inlet manifold having a plurality of outlet ports connected to said inlet ports of said engine, an air entrance leading to said main inlet manifold and having a fuel air mixing chamber therein, a mixture outlet, a main mixture throttle therein, a heated Wall in said inlet manifold located on the engine side of said main throttle before the mixture stream is divided so that all the mixture sweeps over said heated wall before being discharged through said outlet ports, an auxiliary manifold connected to the outlet ports of said exhaust heated inlet manifold and to the mixture outlet on the engine side of the main mixture throttle, an auxiliary throttle in the entrance to said auxiliary manifold, means responsive to the suction in the main mixture chamber and adapted to open said auxiliary throttle, yieldable means adapted to oppose said suction responsive means so as to hold said auxiliary throttle closed during normal engine operation whereby at high engine speeds the mixture temperature at the engine ports falls when the main throttle is opened due to the unheated mixture supplied through said auxiliary manifold.

2. A device as set forth in claim 1 in which the mixture chamber is shaped like a venturi so that the auxiliary throttle is operated by the venturi suction.

DALE GARDNER. 

